It is generally known to incorporate water reservoirs of various types with bowls to gravity feed water to the bowl to replenish water removed from the bowl due to consumption by an animal, spillage, evaporation, etc. Many such prior art arrangements are relatively large and do not readily lend themselves to use when traveling with a pet. Many such devices also spill all or nearly all of the water in the apparatus when tipped or inverted. Because of the structural configuration and high center of gravity of some of these prior art systems, they are inherently unstable and not suitable, for example, for placement on an uneven surface or use in a moving vehicle. Then too, the structural nature of some prior art systems incorporating a reservoir do not allow complete consumption of water in a water supply reservoir nor provide or maintain other than a minimal amount of water available to an animal.
The following patent publications disclose prior art devices of this nature which are believed to be representative of the current state of the prior art in this field: U.S. Pat. No. 3,076,435, issued Feb. 5, 1963, U.S. Pat. No. 6,467,428, issued Oct. 22, 2002, U.S. Pat. No. 5,791,287, issued Aug. 11, 1998, U.S. Pat. No. 5,284,173, issued Feb. 8, 1994, U.S. Pat. No. 6,067,935, issued May 30, 2000, U.S. Pat. No. 6,101,974, issued Aug. 15, 2000, U.S. Pat. No. 7,089,881, issued Aug. 15, 2006, U.S. Pat. No. 6,463,880, issued Oct. 15, 2002, U.S. Design Pat. No. D454,234, issued Mar. 5, 2002, U.S. Design Pat. No. D454,990, issued Mar. 6, 2002, U.S. Design Pat. No. D497,041, issued Oct. 5, 2004 and Japanese Patent Abstract No. 2003299419, issued Oct. 21, 2003.